1. Field of the Invention
The present invention relates generally to apparatus for monitoring patient movement, and more particularly to pressure pad for use on a chair, bed, or other surface typically occupied by a patient or resident and having an operably connected alarm system for alerting staff when the patient or resident has moved outside a defined area. Even more particularly, the present invention relates to a patient monitoring pressure pad having a time sensor and alarm that alerts hospital or residential care staff that the effective life of the pressure pad is nearing its end.
2. Discussion of Related Art including information disclosed under 37 CFR §§1.97, 1.98
Residential care facilities, particularly long-term residential care nursing facilities, must provide a considerable measure of protection to residents who may be impaired in their ability to care for themselves or to exercise sound judgment. Inherent in such care is the need to routinely confine residents to beds, chairs, showers, or other defined spaces or support apparatus, or alternatively to monitor patients and residents to ensure that the same do not wander into unsafe circumstances or outside the watchful care of the staff of the hospital or residential care facility. Accordingly, it is known to provide bed, chair, shower, and room occupancy monitoring systems to alert staff or attendants of inappropriate patient movement or mishaps.
For example, U.S. Pat. No. 5,410,297 to Joseph teaches a bed monitoring system including a capacitive sensor pad for placement under a patient. The pad comprises a foam plastic pad and heavy aluminum foil plates laminated on opposite sides of the foam. The plates are then adhesively bonded to the inner surfaces of an outer cover. The capacitor of the pad is connected in circuit with an oscillator and produces a frequency-related output. A ripple counter establishes a frequency-related output proportional to the capacitance. A microprocessor reads the counter output and samples are averaged to establish a reference base and the true weight affect of the patient on the sensing pad. Other factors which might effect the signal are readily attended to by programmed compensation. Each subsequent sample is averaged and compared with the reference base. If within a permitted range, the latest and current signal is averaged with the reference base and establishes a new base, and continuously tracks changes in the sensing system. A selected change in a selected time delay system actuates an alert or alarm system, which requires positive resetting to terminate the alarm system. The system is positively reset to return to normal position monitoring. The system may be set to automatically reset the alarm system after an alarm condition is established and then removed by the continuous tracking of the patient movement.
Also illustrative of the art, U.S. Pat. No. 5,654,694 to Newham U.S. Pat. No. 5,654,694 to Newham discloses a mobile patient monitoring system. The system includes a load sensor which detects the presence of a patient on a device and further includes a microprocessor responsive to a resident program. A first circuit connected to the microprocessor and to the sensor automatically activates operation of the microprocessor to a “monitor” mode upon detection by the sensor of the patient's presence on the device; it maintains operation of the microprocessor for a predetermined time period at least equal to a running time of the program; and it terminates operation of the microprocessor at the expiration of the predetermined time period after detection by the sensor of termination of the patient's presence on the device prior to expiration of the predetermined time period. A second circuit operates the system in response to commands manually applied to the second circuit to deactivate the system to a “hold/reset” mode after activating of the system to the “monitor” mode. The first circuit will also activate the system to the “monitor” mode after the system has been deactivated to the “hold/reset” mode together with subsequent detection by the sensor of termination of the patient's presence on the device and resumption of the patient's presence on the device. Alternatively, the microprocessor is responsive to the manually operable switch in the second circuit to activate the system to the “monitor” mode after the system has been deactivated to the “hold/reset” mode. A third circuit connected to the microprocessor provides an audio alarm upon demand by the microprocessor.
Patient monitoring pressure pads have a limited time during which their operation is entirely reliable. Accordingly, it is a common practice to have caregivers physical mark the pad with a date to ensure timely replacement before the operation either becomes unreliable or before total device failure. This system of monitoring the patient monitoring pad is unreliable and calls for specific staff action to remember to initiate, and then initiate, an affirmative act to prevent an important care facility device from becoming ineffective. There thus remains a need for a patient monitor pressure pad that provides care facility staff with an indication that the pad is nearing the end of its useful life. Preferably, the indication would be in the form of an audible alarm, such that care facility staff would be required to replace the pressure pad to eliminate an annoying alarm output.
The foregoing patents reflect the current state of the art of which the present inventor is aware. Reference to, and discussion of, these patents is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.